Apparatus for feeding pulverulent material



June 2, 1942. 5. LUNDGREN APPARATUS FOR FEEDING PULVERULENT MATERIALFiled Aug. 31, 1940 2 Sheets-Sheet l IIII-IIIIII lllll A A EricLZUJOfQ'ID.

June 2, 1942. E. LUNDGREN APPARATUS FOR FEEDING PULVERULENT MATERIALFiled Aug. 31, 1940 2 Sheets-Sheet 2 III "En UT Eric Luna 91 611.

Patented June 2, 1942 f UNITED STATES VPATENT'OFFICE" APPARATUS FORFEEDING PULVERULENT MATERIAL Eric Lundgren, Braddock Heights, Md.,assignor to E. B. & A. C. Whiting Company, Burlington, Vt., acorporation of Vermont Application August 31, 1940, Serial No. 355,0102'Olaims. (01. 302-49) This invention relates to apparatus for feedingpulverulent material. More particularly, the invention pertains to meansfor feeding, continuously and at a predetermined uniform rate, into aconduit system, finely divided matterfsuch as ground talc, from a bulkmass of such matter.

Methods for applying a'dust, powder, perfume or other treating agent, ina finely divided form, to a porous, open mesh body, such as a web ofrubberized fibrous material, may include suspending the-dusting agent ina stream of air or other gas circulating within a substantially closedcircuit system, the open mesh material to be'impregnated passing througha portion of the system in such manner that the stream of thus laden gastraverses the open mesh material.

The present invention provides means adapted for feeding ground talc orthe like-into such a conduit system including a hopper, a chamberconnecting the bottom of the hopper with a tube adapted to dischargeinto said conduit system, a spider rotatably disposed in the bottom ofsaid hopper so that the arms of the spider can sweep across the mouth ofsaid chamber to feed talc or the like from the hopper into the chamber,and air jets for displacing talc or the like from the pockets betweenthe arms of the spider into the chamber and thence into the tube. Thespider may be driven by a shaftprojecting upwardly into the hopper andprovided with radial arms that agitate the bulk mass of talc or otherfinely divided matter in the hopper.

Uniformly sized portions of talc or other finely divided matter may thusbe removed from a bulk mass ata predetermined rate ,and blowmfirst intoa chamber and thence into a tube adapted to discharge into a conduitsystem such as theone described hereinabove. Talc or the like maythereby be fed into such a conduit system not only at any desireduniform rate but may also be introduced in the state in which it is tobe utilized in said conduit system, namely, as a gaseous suspension. 1 i

It is therefore an important object of the present invention to provideapparatus for feeding, at

a predetermined uniform rate, finely divided matter from a bulk massinto a conduit system or the like in the form of a gaseous suspension.

Another important object of this invention is to provide, in anapparatus for the purpose indicated including a hopper and a chamberconnecting the bottom of this hopper with a tube adapted to dischargeinto a; conduit system, a spider or the like rotatably disposed in thebottom of the hopper so that the arms of the spider can sweep across themouth of the chamber.

Another object of the invention is to provide,

in an apparatus of the type described in the pre-.

ceding paragraph, air jets for'blowing talc or other finely dividedmaterial from the pockets between the arms of the spider into thechamber and other air jets for blowing the talc thence into the tube;

Still another object is to provide, in an apparatus of the typedescribed in the preceding paragraphs, a shaft for driving the spiderprojecting upwardly into the hopper and provided with radial arms foragitating the bulk mass of finely divided material in the hopper. I

Furtherohjects of the invention include the provision of means andmethods for preventing the rotation of finely divided matter agitated inthe hopper, for preventing the entrance of finely divided matter intojournals of shafts for drivcompanying drawings.

' The invention (in a preferred form) is illustrated in the drawings andhereinafter more fully described.

In the drawings:

Figure l is a fragmentary elevational view of i an apparatus accordingto the present invention.

-Figure 2 is an enlarged fragmentary sectional view along the line II-IIof Figure 1, with certain parts shown in elevation.

Figure 3 is an enlarged fragmentary sectional view along the lineIII--III of Figure 2, with certain parts shown in elevation.

Figure 4 is an enlarged fragmentary sectional View along the line IVIVof Figure 2.

Figure 5 is an enlarged fragmentary sectional view of a modified form ofan apparatus according to the present invention. The view'of Figure 5 istaken along a line similar to thatalong which Figure 4 is taken.

As shown on the drawings:

The reference numeral It) indicates generally an apparatus according tothe present invention. Referring to Figures 1 and 2, theapparatuscomprises a hopper H formed hy an inverted frustoconicalopen-bottomed vessel 12, a' largely tubularmember l3 forming adownwardcontinuation of the vessel I2, and a housing l4 forming thebottom portion of the hopper. A chamber I in the housing I4 connects thehopper with a tube It adapted to discharge into a conduit system (notshown). A spider rotatably disposed in the bottom of the hopper has armsI1 capable of sweeping across the mouth of the chamber I5 (see alsoFigure 4). An air jet I8 is inserted into the tubular member I3 fordisplacing finely divided material indicated by the reference numeral I9from the pockets between the spider arms I1 into the chamber I5 whenceanother air jet inserted into the housing I4 blows the finely dividedmaterial into the tube I5. The chamber I5 is connected to the outeratmosphere by an opening I5A, which permits entrance of air into thechamber I5 to counteract the vacuum which tends to be created by the airjet 20. A shaft 2| for driving the spider projects upwardly into thehopper and is provided with radial agitating arms 22.

As shown more particularly in Figure 2, the hub of the spider projectsupwardly and carries agitating arms 26. The wall of the tubular memberI3 bulges inwardly above the mouth of the chamber I5. The bulge 21 thusformed projects downwardly to define the ceiling of the interspace sweptby the spider arms I1 whose floor is formed by the bottom of the hopperII as constituted by the housing I4. As shown in Figure 3, the bulge 21extends circumferentially on both sides of the mouth of the chamber I5for a distance such that the passage from the hopper II to the chamberI5 is always blocked by at least one spider arm I1 on each side of themouth of the chamber I 5. The air jet I 5 discharges into a radialchannel 28 in the bulge 21 and thence through a plurality of nozzles 29parallel to the' axis into said interspace between the bulge 21 and thefloor of the hopper.

The agitating arms 22 are attached to the shaft 2| by means of a pipesleeve 30 affixed to the shaft 2| by a drive pin 3|.

As shown in Figure 3, the air from the air jet 29 is directed into thedischarge tube I6 by a nozzle 32 in a nipple 33. Another nipple 34serves to attach the discharge tube IE to the housing Referring again toFigure 2, a bushing 31 in the housing I4 journals the shaft 2 I. An airjet 38 serves to admit air through a channel 39 into registering annulargrooves 40 and 4|, formed, respectively, in the lower face of the hub 25and in the opposed upper surface of the housing I4.

The shaft 2| is operatively connected to the hub 25 by a key 42 which,can slide axially in a groove (not shown) in the hub. A set screw 43holds theshaft in any desired position of axial displacement relative tothe hub.

The shaft 2| is driven by a worm gear including a worm shaft 41 and agear wheel 48 grooved (not shown) to effect a sliding fit over a key 49on the shaft 2|. To house the worm gear, the lower part of the housingI4 is expanded radially into bell shape and flanged. A cover 5|! hav-ving a central downwardly projecting boss 5| closes the gear housing thusformed, which is provided with oil 52 through an opening closed by aplug 53.

The boss 5| is pierced by a longitudinal well 55. The upper portion ofthis well holds a bushing 56 journalling the shaft 2 I The lower portionis threaded to receive an externally threaded sleeve 51 spaced from thebushing 56. The lower end portion 58 of the shaft 2|, which is threadedterminally and, as a whole, is of smaller diameter than the rest of theshaft, is journalled in the sleeve 51. the shaft portion 58 on bothsides of the sleeve 51. A nut 60 holds the lower thrust bearing againstthe sleeve 51. The upper thrust bearing is held between the sleeve 51and the shoulder in the shaft 2| formed at the transition point to thereduced end portion 58. A set screw 6| in the boss 5| engaging a leaddisk filo. and covered by a plug 6Ib holds the sleeve 51 in any desiredposition of axial displacement, aided by the lock nut 62. A cap 63shields the lower terminal portion of the shaft end 58.

By adjustment of the threaded sleeve 51 and tightening of the lock nut62 and the set screws GI and 43, the shaft 2| as well as the spider canbe displaced longitudinally relative to the tubular member I3 and thehousing I4 and held in any desired position of displacement. Theclearance of the spider arms H as against the lower surface of the bulge21 and the upper surface of the housing I4 can thus be regulated atwill.

This adjustability makes possible close clearances on both sides of thespider, to prevent siphoning of talc and to effect constant feeding.

Air admitted under pressure from the nozzle 38 into the annular grooves40 and 4| prevents the entrance of finely divided material into the mainjournal of. the shaft 2| formed by the bushing 31.

The agitating arms 22 and 28 keep talc or other finely divided matter inthe hopper I from being hung up or suspended as the lowermost portionsof the finely divided matter are removed by the spider arms I1. Thebulge 21 prevents the finely divided matter from rotating along with theagitating arms 26 and the spider arms I1 andalso serves to restrict thetransfer of finely divided matter from the hopper to the chamber I5 tothat transported by the spider. As the rotation of the latter sweepsfinely divided matter under the bulge 21 and over the mouth of thechamber I5, air from the nozzles 29 dislodges the matter from thepockets between the spider arms into the chamber I5 whence air from thenozzle 32 moves the finely divided matter into the discharge pipe I6 inthe form of a streaming gaseous suspension.

Figure 5 illustrates another device according to this invention. Partssimilar to those described hereinabove are indicated by like numerals.This modified device comprises a disk-like spider B5 pierced by a seriesof round holes 61 adapted to register, on rotation of the disk, with themouth of the chamber I5. A spider of this type limits more efficientlythe movement of certain types of finely divided material from the hopperII to the chamber I5 to material transported in the pockets of thespider. In particular, leakage around the outer edge of the spider isprevented, and a more uniform feeding is obtained.

The feeding apparatus described hereinabove is particularly adapted foruse in conjunction with a conduit system of the type indicated forimpregnating open mesh or porous material. The apparatus, however, isalso applicable for use for all purposes that require means for feeding,at a predetermined uniform rate, finely divided matter from the bottomof a bulk mass into a conduit or the like, without hanging up of thebulk mass and without slugging of the matter being fed. I

It will, of course, be understood that various details of constructionand of operation may be varied through a wide range without departingThrust ball bearings 59 encircle.

from the principles of this invention and it is, therefore, not thepurpose to limit the patent granted hereon otherwise than necessitatedby the scope of the appended claims.

I claim as my invention:

1. In an apparatus for feeding finely divided.

matter from a bulk mass into a conduit comprising a bottomed hopper,means defining a chamber communicating with said conduit and having amouth opening into the bottom of said hopper, a spider having a hubrotatively disposed in the bottom of said hopper for displacing portionsof said finely dividedmatter over the bottom of said hopper to a spaceabove the mouth of said chamber, and a journalled shaft for driving saidspider piercing said hopper bottom, the improvement comprising a spiderhub and a hopper bottom having circular registering. grooves concentricwith and spaced from said shaft, and means for admitting air underpressure into said grooves, to prevent the entrance of finely dividedmatter thereinto.

2. In an apparatus for feeding finely divided matter to a conduitincluding a bottomed hopper, a chamber communicating with said conduitand opening into the bottom of said hopper, a spider for moving finelydivided material over the bottom of said hopper to the space above theopening of said chamber, and a journalled shaft for said spider, theimprovement comprising a spider and a hopper bottom having circularregistering grooves concentric with said shaft, and multiple jet meanscommunicating with a common source of compressed gas, one jet beingdirected into the space above the opening downward into said chamber,another jet being directed into, said chamber and a third jet beingdirected into said grooves, said jets serving to displace finely dividedmatter from the pockets of said spider into said chamber and thence intosaid chamber while excluding the same from said grooves.

ERIC LUNDGREN.

